Albian to Turonian agglutinated foraminiferal assemblages of the Lower Saxony Cretaceous sub-basins – implications for sequence stratigraphy and paleoenvironmental interpretation

Abstract. Albian to Turonian carbonate deposits at three different locations of the Lower Saxony Cretaceous and thereby European mid-Cretaceous epeiric shelf sea were investigated for their fossil agglutinated foraminiferal fauna. In this study, 71 samples from two quarries drill cores treated with formic acid, which enabled study assemblages even in highly lithified limestones. total, 114 species determined classified as belonging nine morphogroups. general, four are distinguished: (1) an uppermost Albian–lowermost Cenomanian assemblage Wunstorf cores, dominant taxa Bathysiphon spp., Nothia Psammosphaera fusca, Reophax subfusiformis, Bulbobaculites problematicus, Tritaxia tricarinata, Flourensina intermedia, Vialovella frankei, Arenobulimina truncata, Voloshinoides advenus; (2) a Baddeckenstedt quarry Ammolagena clavata, (3) related Cenomanian–Turonian Boundary Event Söhlde dominated by problematicus; (4) sections high numbers contorta, Repmanina charoides, Gerochammina stanislawi, Spiroplectammina navarroana. The latest Albian–earliest consists tubular, globular, elongate morphogroups typical low- mid-latitude slope biofacies. All other composed additionally globular forms proximal settings or flattened planispiral streptospiral more distal Wunstorf. For these assemblages, new biofacies named “mid-latitude biofacies” is proposed herein. Changes relative abundance can often be referred single features depositional sequences. Furthermore, classical macro-bioevents, depositional-related, seem have micro-bioevent acme equivalent